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| 新疆萨热阔布金矿床流体包裹体研究及矿床成因 | |
| 引用本文： | 秦雅静,张莉,郑义,刘春发,迟好刚.新疆萨热阔布金矿床流体包裹体研究及矿床成因[J].大地构造与成矿学,2012,36(2):227-239. |
| 作者姓名： | 秦雅静 张莉 郑义 刘春发 迟好刚 |
| 作者单位： | 1. 中国科学院矿物学与成矿学重点实验室,广东广州510640;中国科学院研究生院,北京100049 2. 中国科学院矿物学与成矿学重点实验室,广东广州,510640 3. 招远黄金集团阿勒泰市招金昆合矿业有限公司,新疆阿勒泰,836500 |
| 基金项目： | 本文受国家自然科学基金，国家973项目，国家科技支撑计划项目，中国科学院广州地球化学研究所知识创新工程领域前沿项目资助 |
| 摘 要： | 新疆萨热阔布金矿床位于阿尔泰造山带南缘克兰火山-沉积盆地内,矿体呈脉状产于康布铁堡组上亚组地层中(D1k2)。不同成矿阶段石英脉中广泛发育流体包裹体,可划分为H2O-CO2包裹体(C型)、纯CO2包裹体(PC型)、水溶液包裹体(W型)及含子矿物多相包裹体(S型)四类。测温结果显示,成矿早阶段主要发育C型和PC型包裹体,均一温度范围为271～446℃,流体盐度介于5.9%～8.4%NaCleqv之间;中阶段主要发育C、PC、W和S型包裹体,均一温度低于早阶段,为236～374℃,流体盐度介于4.8%～15.0%NaCleqv之间;晚阶段主要发育W型包裹体,均一温度范围为139～264℃,流体盐度介于1.1%～6.9%NaCleqv之间。对成矿压力和深度的估算表明,成矿压力为90～330MPa,成矿深度为9～12km。综上所述,萨热阔布金矿成矿流体具有富CO2、中低盐度的变质流体特征,流体沸腾导致了成矿物质的沉淀。结合矿床地质特征,萨热阔布金矿床属于造山型金矿床。 |
| 关 键 词： | 流体包裹体 萨热阔布金矿 造山型金矿 阿尔泰造山带 |
Fluid Inclusion Studies and the Genesis of the Sarekuobu Gold Deposit, Xinjiang |
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| QIN Yajing , ZHANG Li , ZHENG Yi , LIU Chunfa , CHI Haogang.Fluid Inclusion Studies and the Genesis of the Sarekuobu Gold Deposit, Xinjiang[J].Geotectonica et Metallogenia,2012,36(2):227-239. | |
| Authors: | QIN Yajing ZHANG Li ZHENG Yi LIU Chunfa CHI Haogang |
| Institution: | 1.Key Laboratory of Mineralogy and Metallogeny, Chinese Academy of Sciences, Guangzhou 510640, Guangdong, China; 2.Graduate University of Chinese Academy of Sciences, Beijing 100049, China; 3.Zhaojin Kunhe Mining Industry Company, Zhaoyuan Gold Industry Group, Altay 836500, Xinjiang, China) |
| Abstract: | The Sarekuobu Au deposit is located in a Devonian volcanic-sedimentary basin of the Altay orogenic belt. Volcanic rocks and sedimentary strata exposed in the area experienced greenschist-facies metamorphism. According to the interrelation of quartz veins, the hydrothermal ore-forming processes of the deposit can be divided into early, middle and late stages, represented by pyrite-quartz, polymetallic sulfide-quartz and carbonate-quartz veinlets, respectively. The early-stage veins or minerals were structurally deformed and brecciated, indicating a compressional or trans-compressional setting. The middle-stage veinlets intruded and filled the fissures of the early-stage assemblages without deformation, suggesting a tensional shear setting. The late-stage veinlets mostly filled open-space of fissures that crosscut and altered the earlier stage veins. Four types of fluid inclusions(FIs) are distinguished, including aqueous (W-type), carbonic-aqueous (C-type), purely carbonic (PC-type) and solid-bearing (S-type). The early-stage quartz contain the C- and PC-type primary FIs, and the homogenization temperatures of the primary C-type fluid inclusions in the early stage quartz range from 271°C to 446°C with salinities ranging from 5.9% to 8.4% NaCleqv The middle-stage quartz trapped C-, PC-, W- and S-type fluids inclusions with the lower temperatures ranging from 236°C to 374°C and higher salinities ranging from 4.8% to 15.0% NaCleqv. Laser Raman analysis indicate that the gases in fluid inclusions are CO2, CH4 and N2. The late-stage quartz veins contain only aqueous fluid inclusions with homogenization temperatures ranging from 139°C to 264°C, and salinities ranging from 1.1% to 6.9% NaCleqv. The low salinity and high CO2 content indicate that the ore-forming fluid may be metamorphic fluid. In the middle stage, coexistence and similar homogenization temperature of C-, W- and S-types indicate that metal precipitation may result from fluid boiling and CO2-escaping. The estimated trapping pressures of boiling FIs assemblage range from 90 to 330 MPa, suggesting an alternating lithostatic-hydrostatic fluid-system, controlled by the fault-valve at the depth of 9~12 km. In the middle stage, fluid boiling caused CO2 escape and metals precipitation, which resulted in the formation of most of the reserves, and meteoric water added to the ore-forming system in the late stage also caused the precipitation of metals. In conclusion, our results show that the Sarekuobu Au deposit in Xinjiang is an orogenic gold deposit. |
| Keywords: | fluid inclusion Sarekuobu Au deposit orogenic Au deposit Altay orogenic belt |
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